The more functional groups a molecule contains, the more likely a reaction is going to fail. Despite this challenge, researchers have developed mild methods to invert a stereocenter late in the synthesis, opening the door to new chemical structures. When synthesizing chiral organic molecules, one diastereomer or enantiomer is often more easily accessible than the others. This typically occurs for two reasons: either the starting material is an enantiomerically pure natural product (such as l-alanine), making its less common enantiomer (d-alanine) necessary in order to obtain the other stereoisomer; or the chosen reaction intrinsically favors...